The present invention relates to a washer-dryer that treats a wash load, which has been thrown into an inner tub disposed rotatably inside an outer tub of the washer-dryer, through a whole process beginning from washing to drying.
A conventional washer-dryer having the above-described functions has been structured as illustrated in FIG. 20. The structure is described below.
Referring to FIG. 20, an inner tub 1 of approximately cylindrical shape, functioning as a tub for both washing and spin-drying operations, is provided rotatably within the inside of an outer tub 2. At the upper part of inner tub 1 is a fluid balancer 3, in the inner bottom is a provided a pulsator 4 that is freely rotatable. The outer tub 2 is housed in a cabinet 6, being suspended by a suspension gear 5 for anti-vibration. A motor 7 is provided at the bottom part of the outer tub 2. The motor 7 has a built-in clutch and gear for conveying the revolving force of the motor to a wash/spin-dry shaft 8, which has an empty dual-shaft structure and switches the transmission to the pulsator 4 or to the inner tub 1 in accordance with a process, washing or spin-drying. The outer tub 2 is connected at the bottom to a drain channel 9 via a drain cock 10. Hot air blowing means 11 comprises an air-blower and a heater (neither is shown); which is attached on the outer tub 2 for supplying hot air inside the inner tub 1 for drying the wash load.
The operation of a washer-dryer of the above structure is described below. In a washing process, a wash load 12 is thrown into the inner tub 1 together with detergent, and water or hot water is supplied therein. The clutch built in the motor 7 is switched to convey the driving force of the motor 7 to the pulsator 4 via a wash shaft. The wash load 12 is stirred by rotation of the pulsator 4.
In a spin-drying process, which follows after the washing process is over, water in the inner tub 1 is discharged by opening the discharge cock 10, and the clutch built in the motor 7 is switched to convey the driving force of the motor 7 to the inner tub 1 via a spin-dry shaft. The inner tub 1 is rotated, and the wash load 12 is provided with a centrifugal force and is spin-dried.
In a drying process, hot air is supplied to inside the inner tub 1 by the hot air blowing means 11 while the pulsator 4 is driven in a normal mode. The wash load 12 is dried by the hot air.
However, in the drying process under the conventional structure as described above, the hot air supplied from the hot air blowing means 11 into the inner tub 1 does not reach to the whole space of inner tub 1; the bottom space, among others, is not provided with a sufficient amount of hot air. Therefore, it is difficult to provide a wash load 12 with a sufficient amount of the heat and the velocity of hot air in an efficient manner. This means that it takes a long time for drying, and that a wash load may not be dried evenly. Furthermore, as the hot air blowing means 11 has been attached on the outer tub 2, the gross weight of the vibrating body formed of the outer tub 2 and the hot air blowing means 11, which have been suspended by the suspension gear 5 from the cabinet 6, is a substantial amount; which results in significant vibration during operation, especially during the spin-drying process.
The present invention addresses the above-described problems, and intends to raise the efficiency of drying performance by reducing the drying time and improving the unevenness of drying. Also intended in the present invention is to alleviate the vibration during operations, especially during the spin-drying process.
An invented washer-dryer comprises an inner tub of approximately cylindrical shape rotating around a substantially vertical axis for receiving a wash load, the inner tub being housed in an outer tub, agitation means disposed rotatably in the inner tub for agitating a wash load, a motor for rotating the inner tub or the agitation means, heating means for heating the air to be supplied through a hot air supply channel into the inner tub, a drying air blower for delivering hot air into the inner tub, and control means for controlling each of the washing, rinsing, spin-drying and drying processes by controlling the operations of the motor, heating means, drying air blower, etc. During the drying process, a wash load is agitated by the agitation means and the air heated by the heating means is blown by the drying air blower against the wash load staying within the inner tub. By so doing, the wash load may be dehydrated and dried within a short period of time, without leaving significant unevenness of drying. Thus, the efficiency of drying is improved. Also, the vibration is substantially alleviated during operation, especially during the spin-drying process.
More desirably, the coupling of a hot air supply channel and an outer tub should be made by using a flexible and expandable tube. With such a structure, even if the inner tub rotating at a high speed generates an oscillating vibration during the spin-drying process, the outer tub may not be jerked in one specific horizontal direction by the hot air supply channel, so it can continue making a natural vibration. Vibration of outer tub caused by the high-speed rotation of inner tub is conveyed evenly to a cabinet. Therefore, the vibration as a whole is suppressed.
Desirably also, the upper part of outer tub should be covered with a separation board for preventing the air from escaping; and a water supply cock for supplying water into the inner tub is connected to an intake of water provided in the separation board by using a water supply duct in order to facilitate the water supply into the inner tub. With such a structure, the hot air is prevented from escaping during the drying process. Thus the drying performance is improved. At the same time, the increase of humidity in the room air due to escaping hot air is avoided.